Last week, 61-year-old Alvin Gibbs put on a boxing exhibition that stopped other fighters at the West Side Boxing Club in their tracks.

With his bare hands, Gibbs tore into a punching bag with thunderous punches, letting out shouts and heavy grunts with each delivery. The hits were delivered with such force that they seemed to lift his stocky, 270-pound frame – nearly 100 pounds more than his professional fighting weight – right off the ground.

A round of applause followed the 30-second deluge of punches for the man known in the gym as “Big Al,” “Father Al” and “Reverend Al.”

“He’s the oldest person in here, and he still hits harder than anybody else,” said Adalberto “Jerry” Diaz, who, like Gibbs, is a volunteer trainer.

Gibbs may have the hardest punch, but Diaz said he is also the softest touch.

“He’s like everyone’s uncle here. If a kid is locked out or needs food or to be taken to a medical appointment, all they have to do is ask him, and everyone knows that,” Diaz said.

Gibbs is the first to say he was a very different person earlier in life – someone to run from rather than toward.

The Alabama native grew up in Buffalo and Niagara Falls, and spent almost 10 of those years living in three foster homes after his mother became sick, before moving back with her and his siblings.

Gibbs was a tough kid with a reputation for being a bruising street fighter. Later, he used and sold drugs, and he was an enforcer for big-time dealers in Buffalo, Rochester and New York City.

“I worked as a bully for a lot of drug dealers, a lot of them. It didn’t take much for me to want to hurt someone,” Gibbs said. “I was a ‘n - with attitude,’ and I had a bad one.”

As the 1970s rolled around, Gibbs embarked on a professional boxing career as a light heavyweight, and worked full time as a furnace operator at Hanna Furnace in Lackawanna.

Gibbs’ career had some successes but never really took off. He said he was paid to spar with three heavyweight champions – Floyd Patterson, Muhammad Ali and Joe Frazier – and that he boxed in the ring with a fourth, Michael Dokes.

Gibbs sparred with Patterson first, prior to a 1971 bout in which the two-time champ beat Buffalo fighter Vic Brown in the old Peace Bridge Arena. Patterson knocked Gibbs down twice over the course of 30 rounds in two days at a gym on Main Street, first with a right hand and later with a left hook.

“When he dropped me, tears were coming to my eyes and everything was bothering me because I wasn’t used to that. But Floyd was the epitome of a gentleman. After he’d drop you, he’d say, ‘Now, this is how you get away from that punch.’ ”

Gibbs trained for a day with Ali at his training camp in Deer Lake, Pa. “It was a lesson like you never saw in your life. It was impossible to hit him,” Gibbs recalled. “He tagged me quite a few times. He beat me up real good but he instructed me.”

Gibbs said Ali also made sure he was paid and looked after in a caring way that was unusual for the often-shady boxing world.

Sparring with Frazier, he recalled, “was a nightmare. Frazier is a hard-hitting man. He knocked me down quite a few times.”

Gibbs’ boxing career and good-paying blue-collar job came to a sudden halt after he punched and killed Elbert Blake in August 1978, in a brief street altercation in Niagara Falls. Gibbs said he tagged Blake once and saw him get up and leave, never realizing the blow would kill him.

He pleaded guilty to first-degree manslaughter, and in April 1979 Gibbs, then 27, began serving a five- to 15-year sentence in Attica prison. He was released in 1985.

Several years later, Gibbs became a committed Christian, and today is a minister at St. John Baptist Church.

“God has shown me the right way, and that way I can make amends with myself, God and the community,” he said.

Despite his faith, he said he hasn’t forgotten the suffering he inflicted on people. Asked if it weighs on his mind, he said, “Always, always, always.”

It’s one reason why Gibbs, who is married and has five children, ages 22 to 45, and is maintenance supervisor for PUSH Buffalo, helps aspiring boxers at the gym.

“I want to be able to get some of these real tough kids and pull them off the streets, talk to them and help them out. I just want to do something to help somebody, give back a little bit.”

Those at the gym say the popular “Big Al” – whose booming voice can often be heard shouting instructions to fighters listening in rapt attention – gives back plenty.

“He’s like a father to all of us out here,” amateur fighter Rondy Bulls said. “When he talks to you he looks you in the eye so you know he really cares about you, and he means it.”